Mint Is A Weird Flavour, How Can Something Taste Like Cold?

what the article doesn’t tell you is that this has happened once before, and she forgot how to use her drill. she remembered how to drill later one, but then she shut down again for no clear reason. it is still unclear if she remembers how to drill. i love her so much

This is still my favorite chemistry meme

Absence of Serotonin Alters Development and Function of Brain Circuits

Researchers at Case Western Reserve University School of Medicine have created the first complete model to describe the role that serotonin plays in brain development and structure. Serotonin, also called 5-hydroxytryptamine [5-HT], is an important neuromodulator of brain development and the structure and function of neuronal (nerve cell) circuits. The results were published in the current issue of The Journal of Neurophysiology online.

“Our goal in the project was to close the gap in knowledge that exists on role of serotonin in the brain cortex, particularly as it concerns brain circuitry, its electrical activity and function,” said Roberto Fernández Galán, PhD, Assistant Professor in the Department of Neurosciences at Case Western Reserve University School of Medicine. “For the first time, we can provide a complete description of an animal model from genes to behavior—including at the level of neuronal network activity, which has been ignored in most studies to date.”

Dr. Galán and his team used high-density multi-electrode arrays in a mouse model of serotonin deficiency to record and analyze neuronal activity. The study supports the importance of the serotonin which is specified and maintained by a specific gene, the Pet-1 gene – for normal functioning of the neurons, synapses and networks in the cortex, as well as proper development of brain circuitry. Serotonin abnormalities have been linked to autism and epilepsy, depression and anxiety. By more fully elucidating the role of serotonin in the brain, this study may contribute to a better understanding of the development or treatment of these conditions.

“By looking at the circuit level of the brain, we now have new insight into how the brain becomes wired and sensitive to changing serotonin levels.” added Dr. Galán.

Glutamate, an essential food for the brain

Glutamate is an amino acid with very different functions: in the pancreas, it modulates the activity of the pancreatic ß-cells responsible for insulin production, whereas in the brain it is the main excitatory neurotransmitter. In recent years, it has been suspected to play an additional role in the functioning of the brain. By discovering how the brain uses glutamate to produce energy, researchers at the University of Geneva (UNIGE) confirm this hypothesis and highlight unexpected links with the rest of the body. To read in Cell Reports.

Unlike other organs, the brain cannot draw its energy from lipids, an energy resource widely present in the body. The blood-brain barrier, which protects it from the pathogens and toxins circulating in the blood, indeed limits the passage of these lipids. Moreover, while most of the organs in the human body have the ability to store glucose by increasing their mass, the brain, prisoner of the cranial bones, cannot count on these variations in volume. Unable to store its food, it depends on sugar supplied in real-time by the rest of the body. This distribution of energy is controlled by the liver.

Pierre Maechler, professor at the Faculty of Medicine at UNIGE, and his team therefore decided to verify if glutamate was indeed an energy source for the brain. To do so, the researchers analyzed the role of the glutamate dehydrogenase enzyme in the brain. In mutant form, this enzyme, encoded by the Glud1 gene, is responsible for a congenital hyperinsulinism syndrome, a severe disease affecting at the same time the endocrine pancreas, the liver and the brain. Individuals affected by this syndrome suffer from intellectual disability and have a high risk of epilepsy. “We have suppressed the Glud1 gene in the brain of mice. In the absence of glutamate dehydrogenase, we observed that the brain was no longer able to convert glutamate into energy, even though the amino acid was present in the brain,” explains Melis Karaca, first author of this study.

Priority to the brain

Devoid of the energy supplied by cerebral glutamate, the brain sends signals to the liver to requisition a compensatory proportion of glucose, at the expense of the rest of the body. This is why the transgenic mice also showed a growth deficit and muscle atrophy. “This clearly shows how the brain works in a just-in-time manner and that each percent of energy resources is essential for its proper functioning,” highlights Professor Pierre Maechler. “If a part of this energy disappears, the brain serves itself first and the rest of the body suffers. The liver must then make more glucose by drawing upon muscle protein, resulting in loss of muscle mass. Knowing that the brain uses glutamate as an energy resource allows us to reflect on other ways to overcome a potential shortfall. ”

Scientists also suspect a correlation between the Glud1 gene and some neurodevelopmental disorders, particularly epilepsy and schizophrenia. They are currently pursuing their research by introducing in mice the same Glud1 mutation detected in epileptic patients. At the same time, another group is working with schizophrenic patients to assess the way their brain uses glutamate.

Missed any of the graphics featured in C&EN? They’ve now put a page together so you can find all of the graphics in one place, on subjects including Guinness, daffodils, barbecue & more: ow.ly/RB10e

For more posts like these, go to @mypsychology​

It’s ‪#‎InternationalKissingDay‬! Here’s some topical lipstick chemistry. More info/high-res image: http://wp.me/s4aPLT-lipstick

Monkey sees… monkey knows?

Socrates is often quoted as having said, “I know that I know nothing.” This ability to know what you know or don’t know—and how confident you are in what you think you know—is called metacognition.

When asked a question, a human being can decline to answer if he knows that he does not know the answer. Although non-human animals cannot verbally declare any sort of metacognitive judgments, Jessica Cantlon, an assistant professor of brain and cognitive sciences at Rochester, and PhD candidate Stephen Ferrigno, have found that non-human primates exhibit a metacognitive process similar to humans. Their research on metacognition is part of a larger enterprise of figuring out whether non-human animals are “conscious” in the human sense.

In a paper published in Proceedings of the Royal Society B, they report that monkeys, like humans, base their metacognitive confidence level on fluency—how easy something is to see, hear, or perceive. For example, humans are more confident that something is correct, trustworthy, or memorable—even if this may not be the case—if it is written in a larger font.

“Humans have a variety of these metacognitive illusions—false beliefs about how they learn or remember best,” Cantlon says.

Because other primate species exhibit metacognitive illusions like humans do, the researchers believe this cognitive ability could have an evolutionary basis. Cognitive abilities that have an evolutionary basis are likely to emerge early in development.

“Studying metacognition in non-human primates could give us a foothold for how to study metacognition in young children,” Cantlon says. “Understanding the most basic and primitive forms of metacognition is important for predicting the circumstances that lead to good versus poor learning in human children.”

Cantlon and Ferrigno determined that non-human primates exhibited metacognitive illusions after they observed primates completing a series of steps on a computer:

The monkey touches a start screen.

He sees a picture, which is the sample. The goal is to remember that sample because he will be tested on this later. The monkey touches the sample to move to the next screen.

The next screen shows the sample picture among some distractors. The monkey must touch the image he has seen before.

Instead of getting a reward right away—to eliminate decisions based purely on response-reward—the monkey next sees a betting screen to communicate how certain he is that he’s right. If he chooses a high bet and is correct, three tokens are added to a token bank. Once the token bank is full, the monkey gets a treat. If he gets the task incorrect and placed a high bet, he loses three tokens. If he placed a low bet, he gets one token regardless if he is right or wrong.

Researchers manipulated the fluency of the images, first making them easier to see by increasing the contrast (the black image), then making them less fluent by decreasing the contrast (the grey image).

The monkeys were more likely to place a high bet, meaning they were more confident that they knew the answer, when the contrast of the images was increased.

“Fluency doesn’t affect actual memory performance,” Ferrigno says. “The monkeys are just as likely to get an answer right or wrong. But this does influence how confident they are in their response.”

Since metacognition can be incorrect through metacognitive illusion, why then have humans retained this ability?

“Metacognition is a quick way of making a judgment about whether or not you know an answer,” Ferrigno says. “We show that you can exploit and manipulate metacognition, but, in the real world, these cues are actually pretty good most of the time.”

Take the game of Jeopardy, for example. People press the buzzer more quickly than they could possibly arrive at an answer. Higher fluency cues, such as shorter, more common, and easier-to-pronounce words, allow the mind to make snap judgments about whether or not it thinks it knows the answer, even though it’s too quick for it to actually know.

Additionally, during a presentation, a person presented with large amounts of information can be fairly confident that the title of a lecture slide, written in a larger font, will be more important to remember than all the smaller text below.

“This is the same with the monkeys,” Ferrigno says. “If they saw the sample picture well and it was easier for them to encode, they will be more confident in their answer and will bet high.”

from the Fresh Paleomemes fb group

If Earth had Saturn’s Rings

From an excellent post by Jason Davis

From Washington, D.C., the rings would only fill a portion of the sky, but appear striking nonetheless. Here, we see them at sunrise.

From Guatemala, only 14 degrees above the equator, the rings would begin to stretch across the horizon. Their reflected light would make the moon much brighter.

From Earth’s equator, Saturn’s rings would be viewed edge-on, appearing as a thin, bright line bisecting the sky.

At the March and September equinoxes, the Sun would be positioned directly over the rings, casting a dramatic shadow at the equator.

At midnight at the Tropic of Capricorn, which sits at 23 degrees south latitude, the Earth casts a shadow over the middle of the rings, while the outer portions remain lit.

via x